添加Sb_2O_3对NBT基陶瓷介电和铁电性能的影响

Study on Dielectric and Ferroelectric Properties of NBT-based Lead-free Piezoelectrics Doped by Sb_2O_3

采用传统电子陶瓷的制备工艺，制备出微量BiSbO3固溶的（Na0.5Bi0.5）TiO3（NBT-xBS，x=0～0．03）陶瓷，并对其结构、介电及铁电性能进行了研究。Ⅺ射线衍射分析结果表明四种配方均形成了钙钛矿结构晶相。扫描电镜分析显示BiSbO3的引入有助于烧结形成致密的多晶结构。随着BiSbO3固溶量的增加，样品的介电常数减小，而介电损耗基本不变，陶瓷的弛豫性增强，是由于BiSbO3的引入使得晶体结构中A和B位离子排列更加无序造成的。BiSbO3的固溶使NBT仍保持较高的极化强度，矫顽场从7．3kV／mm降至4kV／mm，从而在一定程度有效解决了NBT高矫顽场的问题。

The NBT piezoelectric ceramics with drop BiSbO3 （x=0, 0.01, 0.02, 0.03） were prepared by the conventional ceramic technique. Dielectric and ferroelectric properties of series samples were discussed systematically. From XRD results, it was found a formation of single phase of perovskite structure in series samples. Scanning electron microscope （SEM） micrographs of the natural surface of samples indicated that the compact structure was obtained. With the increase content of BiSbO3, the dielectric constant of the samples decreased remarkably, the relaxation characters of samples were enhanced, while the dissipation factors kept stable, which attributed to more disorder of A and B sites in the lattice structure. The results showed that the introduction of BiSbO3 into NBT-based ceramics has reduced the coercive force remarkably from 7.3 kV/mm to 4 kV/mm, maintaining the large saturation polarization, which meant that the problem of high coercive field could be solved efficiently.